Dude...no offense but if a short is kicking your ass you DO NOT want to change the whole harness out, however "painless" it might sound...

You're talking about the tail light/dash light/running light circuit? That shit is a bitch. The wire is red with a blue stripe and it is pretty much everywhere in the harness. Check all your wires near the connectors at the front marker lights, rear markers, tag lights, tail lights, and fogs/DRLs if you have them...

I spent about 8 hours trying to hunt down a short in that same circuit....lol. Turned out to be the fog light wires were welding themselves together.

If all else fails just hook the lights to a 12v source and ride out...GL